The solid oxide fuel cell (SOFC) power generation system is a device which can convert chemical energy into electric energy directly, usually utilizing light hydrocarbon such as natural gas as fuels, and the chemical energy in the fuels is converted into the electric energy efficiently and cleanly. The distributed power station based on the SOFC power generation system may conveniently utilize the natural gas supplied from the existing natural gas pipeline network to generate electricity, and can provide power to the power grid, therefore, the SOFC power generation system is a power generation method with great commercial prospects.
The core component of the SOFC power generation system is the stack array, which consists of a plurality of stacks in a certain structure of distribution, and the reaction of power generation occurs in the stack array. As the raw material of the light hydrocarbon such as natural gas is supplied into the SOFC power generation system, the raw material is firstly subjected to a reforming reaction in the reformer, then the reformed gas is supplied into the stack array to generate power. Therefore, the stack array of the SOFC power generation system is a power generation component.
The configuration of the stack array is one of the key factors in the design of the SOFC power generation system. In order to improve the efficiency and stability of the stacks, the following needs to be done: 1) in the stack array, the stacks should have a good pressurized fastening mechanism in which a uniform pressure is applied on each of the stacks, so as to improve the efficiency of the stacks; 2) in the stack array, the gas pipelines should be in a proper arrangement to reduce external pipelines as possible, so as to reduce the complexity in pipeline connection; 3) when a fault occurs in a stack in the stack array, it should be easy and convenient to detach, repair and replace the single stack, while the other normal stacks surrounding the faulted one should not be affected.
In the existing design scheme of the SOFC power generation system, such as in American patents U.S. Pat. No. 7,659,022B2 and US 2012/0178003A1, FIG. 1 illustrates the structure of the stack array 1′, which is a ring-shaped array of a plurality of stack groups 2′ disposed in a circular shape; each of the stack groups 2′ consists of a plurality of stacks 4′ stacked in the vertical direction; as shown in FIG. 2, each of the stacks 4′ is arranged vertically, that is, the plane where the gas inlet and the gas outlet of each of the stacks 4′ are located is approximately horizontal. The stack array 1′ further comprises a reformer 3′ supplying gas to the stack array. However, in the above mentioned structure, the stacks are directly stacked in the vertical direction and overall pressurized in the vertical direction, and there exist the following problems: 1) the number of the pipelines for connection, specifically the number of the external pipelines is greatly increased, which increases the complexity in the integration of stacks and reduces the reliability of the stack array; 2) it is not convenient for the repair and maintenance of the stack array, particularly, when a fault occurs in one or more stacks in the stack array and the faulted stack needs to be replaced with new one, the pressurizing mechanism in the related art is not convenient for the replacement of the faulted stacks; 3) vertical pressurizing may generate non-uniform distribution of vertical pressure on each of the stacks, reducing the stability and reliability of the stacks and further influencing the reliability of the overall stack array.